1. Field
The embodiments discussed herein relate to a CRUM chip and image forming device for communicating mutually and method thereof, and more particularly, to a Customer Replaceable Unit Monitoring (CRUM) chip and image forming device for communicating mutually for detecting whether data is integral, using integrity detection data in a communication process, and a method thereof.
2. Description of the Related Art
As computers increasingly becoming widespread, the dissemination rate of peripheral devices of computers is also increasing. Computer peripheral devices include image forming devices such as printers, facsimiles, scanners, copy machines, and multi-function printers.
Image forming devices may use ink or toner to print images on paper. Ink or toner is used each time an image forming operation is performed, and thus runs out when used for more than a predetermined period of time. In such a case, the unit in which the ink or toner is stored has to be replaced. Such parts or components which are replaceable in the process of using an image forming device may be defined as consumable units or replaceable units. For convenience of explanation, these will be referred to as consumable units in this document.
In addition to these units which must be replaced due to depletion of ink or toner as discussed above, there are also consumable units having characteristics that change when the units are used for more than a certain period of time, and thus are replaced to achieve a satisfactory printing quality. Consumable units include color replacement for developing machines, and parts such as intermediate transfer belts.
In the case of laser image forming devices, electrification units, intermediate units or settlement units may be used, in which various types of rollers and belts used in each unit may be worn out or degenerated when used for more than the marginal life span. Accordingly, the quality of image may be severely deteriorated. A user must replace each component, that is, each consumable unit at an appropriate replacing period so that printing operation can be performed to produce clean images.
To manage consumable units more efficiently, memories may be attached to consumable units, so as to exchange information with the body of an image forming device.
That is, it is possible to record various usage information such as the number of printed paper, number of output dots, and usage period into the memory of the consumable unit, for management of a time to replace the consumable unit.
For such information management, a controller provided in the body of an image forming device and a memory unit provided in the consumable unit communicate with each other. However, there are numerous variables in the communication process. For instance, there may be noise interruption caused, for example, by an electronic circuit or motor provided, for example, in the image forming device, or an attack by a hacker who tries to control the controller or the memory unit for malicious purposes.
Communication data may change due to these variables. For instance, once a job is completed, a consumable unit may transmit information such as the number of printing pages, number of dots, and remaining toner volume to a controller, and copies the information to a nonvolatile memory of the controller. Upon the data being read as an incorrect value, for example, such as 0xFFFFFFFF, there is a risk that the controller may perceive that the life of the pertaining consumable unit has ended. In this case, the consumable unit will not longer be able to be used. In contrast, regarding a consumable unit of which the life span has ended, a hacker may reset the consumable user information, for example, to a value of “0” with a malicious purpose, in order to inappropriately recycle the consumable unit. Accordingly, a user may attempt to use a consumable unit of which the life has ended, causing problems such as breakdown of the image forming device or deterioration of definition.
Accordingly, the necessity for a technology which efficiently detects communication errors between a consumable unit, and an image forming device to seek safety of the data is required.